Railway switch controlling apparatus



Nov. 2, 1937. H. s. YOUNG 2,097,826

RAILWAY SWITCH CONTROLLING 'APPARATUS Original Filed Nov. 24, 1934 INVENT OR fienrg S. YbLLng.

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m5 A TTORNEY Patented Nov. 2, 1937 UHTED STATES RAILWAY SWITCHCONTROLLING APPA- RATUS Application November 24, 1934, Serial No.754,616 Renewed March 31, 1937 21 Claims.

My invention relates to railway switch controlling apparatus, andparticularly to apparatus of the type involving a polarized relaycontrolled by a manually operated pole-changer, which relay in turncauses movements of the switch to normal and reverse positions.

One feature of my invention is the use of a polarized relay which is soconstructed that its neutral front contacts remain closed while itspolar contacts are operated from one extreme position to the other by aquick reversal of polarity of the current supplied to its windings.

The apparatus of my invention is an improvement over that disclosed inthe copending applications Serial No. 313,772, filed October 20, 1928,

by Howard A. Thompson for Multiple control apparatus; Serial No.323,266, filed December 3, 1928, by Lester E. Spray, for Multiplecontrol apparatus; Serial No. 416,061, filed December 23, 1929, byHoward A. Thompson for Multiple control apparatus; and Serial No.695,294, filed October 26, 1933, by Earl M. Allen and Howard A. Thompsonfor Interlocking control apparatus.

I will describe three forms of apparatus embodying my invention, andwill then point out the novel features thereof in claims.

In the accompanying drawing, Fig. l is a diagrammatic view showing oneform of apparatus embodying my invention for controlling a fluidpressure mechanism M for operating a railway track switch H Fig. 2 is amodification of a portion of the apparatus shown in Fig. l forcontrolling an electric motor mechanism N for operating track switch HFig. 3 is a modification of a portion of the apparatus shown in Fig. 2for also controlling an electric motor mechanism N for operating arailway track switch H Similar reference characters refer to similarparts in each of the views.

Referring first to Fig, l, the reference characters l and l designatethe track rails of a stretch of railway track Y which is divided byinsulated joints 2 into sections B-C, CD and D-E. Each of these sectionsis provided with a track circuit such, for example, as is shown forsection D-E, comprising a battery designated by the reference character3 connected across the rails adjacent one end of the section, and arelay designated by the reference character T connected across the railsadjacent the opposite end of the section.

Located in section D-E, is a switch H for connecting track Y with asecond track Z. Switch H is operated by a fluid pressure mechanism M,comprising a normal control magnet 1m, a reverse control magnet rr, anda master control or lock magnet q. In section CD, there is a similarswitch H At point C, a signal S is shown for controlling eastboundtrafiic movements, that is, trafiic movements from left to'right, asshown in the drawing, over switches H and H Normal and reverse switchcontrol magnets mi and T1" for mechanism M are controlled by a polarcontact 21] of a polarized switch control relay m in its normal or itsreverse position, respectively. Lock magnet q for mechanism M iscontrolled by back contacts 2i and 22 of normal and reverse indicationrelays which are designated by the reference characters 2' and t,respectively.

Polarized switch control relay m is so constructed that if the polarityof the current supplied to its windings is quickly reversed, its neutralfront contacts operated by its neutral armature will remain closed whileits polar contacts are operated by its polar armature from one extremeposition to the other. Relay m is controlled by an approach lockingrelay P, a route locking relay V, track relay T, its own neutral andpolar contacts 8, 9 and i2, and polechanging contacts 3, i6, H and E6 ofa manually operable device which may be a lever is.

Approach locking relay P may be controlled in any suitable manner such,for example, as shown for relay L in a Patent No. 1,956,851, which wasgranted May 1, 1934, to C. A. Brooks and J. M. Pelikan, for Railwaytraffic controlling apparatus. The manner in which relay P is controlledprevents an operator from changing the position of switch H until ameasured period of time has elapsed after signal S has been caused toindicate stop, if an eastbound train has entered ection B-C while signalS is indicating caution or proceed.

Route locking relay V is so controlled that switch H cannot be operatedwhile an eastbound train occupies section CD.

Lever It has a normal position n and a reverse position 1. Lever 74:operates four contacts, two of which, contacts t and IE1 are closed whenlever k is in its position 17., and the other two of which, contacts iiand I3, are closed when lever k is in its position 1".

On account of relay in having the characteristic that its neutralcontacts 8 and I2 remain closed while its polar contact 9 is moved fromone of the extreme positions to the other by a quick reversal ofpolarity of the current supplied to its winding, relay m can becontrolled by a circuit through either its contact 8 or its contact I2to operate its polar contact 9 if relays P, V and T are energizechbut ifone of these relays is deenergized when the operator moves 1ever is fromits n to its r position or from its r to its n position, relay m willnot reverse its polar contacts until lever is is again placed in theposition corresponding to the position of polar contact 9 of relay 112while all of the relays P, V and T are energized. In this way, controlstorage for relay m is prevented.

Operated in conjunction with switch H is a pole-changer M. A polarizedswitch indication relay h is so controlled by pole-changer it that itbecomes en rgized in the normal or the reverse direction according asswitch H is operated to its normal or its reverse position,respectively.

A normal indication relay, designated by the reference character 2, anda reverse indication relay, designated by the reference character t, areassociated with switch H Relay 2 is controlled by a neutral frontcontact and by a normal polar contact of the polarized-indication relayh and by a. normal polar contact of the polarized control relay m aswell as by a back contact of reverse indicat on relay t. Relay t iscontrolled by a neu- 7 tral front and a reverse polar contact of thepolarized indication relay h and by a reverse polar contact of relay mas well as by a back contact of normal indication relay i.

Referring now to Fig. 2, an electric motor mechanism N, comprising anarmature 33 and a field Winding 35, is here shown for operating switch HOperations of mechanism N are controlled by normal and reverse switchrelays f and g, respectively. Included in each of the circuits formechanism N is a pickup winding 32 of an overload relay W in multiplewith a resistor 3!. The normal operating current for mechanism N isinsufi'lcient to cause relay W to operate'its contact 2'5. Resistor 3|has a positive temperature coeflicient of resistance, and hence ifmechanism N draws an excessive amount of current as, for example whenthere is some obstruction to the movement of switch H resistor 3! willbecome heated by such excess current, causing an increase in itsresistance, Due to the increase in resistance of resistor 3|, thecurrent flowing through winding 32 of relay W will be still furtherincreased, causing contact 2! of relay W to be operated by a lowerexcess current that would otherwise be necessary.

Also operated in conjunction with switch H are normal and reverse switchcontacts 26 and 25,, respectively. Contact 26 is arranged to be closedat all times except when switch I-I occupies its reverse position.Contact 25 is arranged to be closed at all times except when switch I-Ioccupies its normal position.

In order to select between currents of opposite polarities, there areincluded, in the circuits for normal and reverse switch relays f and g,asymmetric units designated by the reference character a withdistinguishing exponents. These units a may be of the Well-known copperoxide rectifier valve type. Relays f and g are also controlled by switchcontacts 25 and 25, respectively, and by the back point of contact 27 ofrelay W as well as by neutral contacts 23 and 29 and polar contacts E iand 23 of relay m. Relay m may be controlled exactly as shown in Fig. 1.

Relay W, when mechanism N draws an excessive amount of current, opensits contact 2'! at the back point, thereby breaking the circuit for cuitfor lock magnet q is open at contact 2| relays f and g, and closes itscontact 21 at the front point, thereby completing one of the stickcircuits for relay W through its holding winding 35. The stick circuitsfor relay W are so controlled by relay m that the current in each stickcircuit flows through the holding winding of relay W in the samedirection as the current in the corresponding pick-up circuit flowsthrough the pick-u winding of relay W.

In Fig. 3, switch H is shown operated by an electric motor mechanism Nas in Fig. 2. Relays m, f and g and holding winding 36 of relay W may becontrolled exactly as for Fig. 2.

The operating circuits for mechanism N, constituting also the pick-upcircuits for winding 32 of relay W, however, differ from those shown inFig. 2, in order to provide a snubbing circuit of lower resistance forarmature 33 of electric motor mechanism N, involving the use of tworesistors 31 and 38 each of which has a positive temperature coefiicientof resistance. The normal operating circuit for mechanism N includesresistor 37 in multiple with a series path through resistor 38 andpick-up winding 32 of relay W. The reverse operating circuit formechanism N includes resistor 38 in multiple with a series path throughresistor 37 and in the opposite direction through pick-up winding 32 ofrelay W.

Having described, in general, each of three forms of apparatus embodyingmy invention, I with now trace in detail the operation of these variousforms of apparatus.

As shown in the drawing, all parts are in the normal condition, that is,track relay T is energlzed; switch lever is is in its normal position n;switches H and H are in the normal position; signal S is indicatingstop; relays h, i, m, P and V, and normal switch control magnet m1. areenergized; and relays t, f, g and W are deenergized.

I will first trace the operation of the form of apparatus shown in Fig.1.

One circuit by which relay m is energized passes from terminal :c of asuitable source of current not shown in the drawing, through contact 4of lever is, contact of relay P, contact 5 of relay V, contact I ofrelay T, winding of relay m, contact 8 of relay m, and contact I G oflever is back to terminal o of the same source of current. A secondcircuit'which is also closed for relay m is the same as the circuit justtraced except that it includes contact 9 of relay m in its left-handposition instead of contact 8 of relay m. Current flowing in each ofthese circuits is of normal polarity, and hence relay m is energized inthe normal direction.

On account of switch H being in its normal position, pole-changer l4,operated in conjunction with switch H is in its normal position, andhence relay h is energized by current of normal polarity. With relays hand m energized by current of normal polarity, normal indication relay iis energized by a circuit passing from terminal .71, through contacts l5and N5 of relay h, contact I! of relay t, winding of relay i, andcontact IQ of relay m to terminal 0.

With relay m energized in the normal direction, normal control magnet 1mis energized by a circuit passing from terminal :13, through contact 20of relay m in its left-hand position, and the winding of magnet 1m toterminal 0. The cirof relay 1'.

I will assume that with all parts of the apparatus thus in the normalcondition, the operator desires to reverse switch H He will thereforemove lever Zc toits reverse position 1", completing a circuit for;energizing relay m in the reverse direction, this circuit passing fromterminal ac, through contact H of lever k, contact l2 of relay m,winding of relay m, contacts I, B: and 5 of relays T, V and P,respectively, and contact l3 of lever k to terminal 0. ,Relay m,beinglthus energized by current of reverse polarity, will shift itspolar contactsfi; i9 and 2.0 from the normal or left-hand position, asshown in the drawing, to the reverse or right-hand position. Such anoperation of relay m can be accomplished if the manipulation of leverit, from. its 11. to its 1" position, is quick enough to close thereverse operating circuit for relay m through contact l2 of relay mbefore this contact opens,

With relay m energized in the reverse direction, thecircuit for relay iis opened at contact I9 of relay m. Back contact 2| of relay 2 thereforecompletes a circuit for lock magnet q, passing from terminal :2, throughcontacts 2! and 22 of relays i and t, respectively, and the winding ofmagnet q to terminal 0. With relay m energized in the reverse direction,reverse control magnet 77 will be energized by its circuit passing fromterminal :13, through contact 20 of relay m in its right-hand position,and the winding of magnet T1 to terminal 0. With magnets q and. 1tenergized, mechanism M will operate switch H to its reverse position.

Upon the completion of the operation of switch H to its reverseposition, pole-changer [4 will be shifted to its reverse position,causing relay h to be energized, by current of reverse polarity. Withrelay h energizedby current of reverse polarity and with relay in stillenergized by current of reverse polarity, a circuit will be completedfor energizing reverse indication relay 15, passing from terminal as,through contact [5 of relay h, contact I6 of relay h in its right-handposition, winding of relay t, contact |8of relay 2', and contact I9 ofrelay m in its right-hand position to terminal 0. Relay 72, uponbecoming energized, opens its contact 22, thereby breaking the circuitfor lock magnet q.

When the operator desires to return switch H to the normalposition, hewill return lever is from its 1' to its n position, causing relay m toagain become energized in the normal direction by its circuit previouslytraced through its own contact 8, although the circuit through itscontact 9 is now open. With relay m energized in the normal direction,thecircuit'traced for relay t will be opened at contact is of relay m.The circuit previously traced for lock magnet q will therefore again beclosed, and the circuit for normal control magnet 1m, previously traced,will again be completed, causingmechanism M to return switch H to itsnormal position.

Upon the completion of the operation of switch H to its normal position,pole-changer M will be returned to its normal position, causing relay hto again be energized by current of normal polarity. With relays h and menergized by current of normal polarity, relay 1' will again beenergized by .its circuit previously traced, causing the circuit formagnet q to again be opened at contact 2|.

I will next assume that, with all parts again in the normal condition,the operator clears signal S for an eastbound traffic movement overswitches I-1 and H The operation for clearing signal S causes relay P tobedeenergized.

I will further assume that a train then enters section B-C, andafterward proceeds into section CD, and then into section D-E. While thetrainis in section C-D, relay V will be deenergized, and while the trainis insection D--E, relay T will be deenergized.

I will also assume that while one of the relays P, V and T isdeenergized, the operator, by mistake, attempts to reverse switch H bymoving le-, ver k to its 1' position. With any one of the relays P, Vand T deenergized, relay m will also be deenergized, and hence, onaccount of contact !2 of relay m being open, the operation of. lever kto its 1* position can not complete the reverse energizing circuit forrelay m. Assuming that the operator does not return lever 70 to itsnormal position, and that all of the relays P, V and T again becomeenergized, the reverse energizing circuit for relay m will still not becompleted on account of contact 12 of relay m being open and contact 9of relay m being in its normal position.

In order to energize relay m in the reverse direction, the operator mustreturn lever is to its 11. position, thereby completing the normalcontrol circuit for relay m through its polar contact 9 in the left-handposition. This will cause contacts 8 and I2 of relay m to be closed, andthe operator can then complete the reverse energizing circuit,previously traced for relay m through its contact 12, by again reversinglever it.

It follows that if the operator changes the position of lever is whileone of the relays P, V and T is deenergized, subsequent energization ofthese relays will not cause relay m to be energized in the directioncorresponding to the changed position of lever 70, and hence the storageof control for relay in is prevented.

I will next describe the operation of the form of apparatus shown inFig. 2. With all parts in the normal condition, relay m will beenergized in the normal direction as shown in Fig. 1.

I will asurne that the operator desires to reverse switch II He willtherefore move lever is to its r position for energizing relay m bycurrent of reverse polarity. With relay m energized by current ofreverse polarity, its polar contacts 24 and 28 will be operated to theright-hand position, thereby completing a circuit for energizing reverseswitch relay 9, passing from terminal at, through contact 23 of relay m,contact 24 of relay m in its right-hand position, back point of contact2? of relay W, asymmetric units at and a winding of relay g, contact 26of switch H contact 28 of relay m in its right-hand position, andcontact 29 of relay m to terminal 0.

Relay 9, upon becoming energized, completes the reverse operatingcircuit for mechanism N, passing from terminal :0, through the frontpoint of contact 34 of relay 9, armature 33 of motor mechanism N,resistor 3! in multiple with winding- 32 of relay W, back point ofcontact 30 of relay 1, and field winding 35' of electric motor mechanismN to terminal 0. Under normal operating conditions, the current flowingin this circuit will cause mechanism N to move switch H to the reverseposition, but will not be of sufficient magnitude to cause relay W tolift the finger of contact 2? from the back point to the front point.Upon the completion of the operation of switch H to the reverseposition, contact 26 will be opened, thereby breaking the circuit justtraced for relay 9.

When the operator desires to return switch H to the normal position, hewill return leverflc to its n position, causing relay m to again becomeenergized by current of normal polarity. Relay m will thereuponcompletea circuit for energizing' normal switch relay 1, this circuit passingfrom terminal :0, through contact 23 of relay m, contact 24 of relay min its normal position, asymmetric units a and a winding of relaycontact 25 of switch H which became closed during the operation ofswitch H to the reverse position, back point of contact 2'! of relay W,contact 28 of relay m in its left-hand position, and contact 29 of relaym to terminal 0.

Relay 1, upon becoming energized, completes the normal operating circuitfor mechanism N, passing from terminal a, through the front point ofcontact 33 of relay f, resistor 3| in multiple with winding 32 of relayW, armature 33 of mechanism N, back point of contact 34 of relay g, andfield winding 35 of mechanism N to terminal 0. current flowing in thiscircuit will cause motor N to return switch H to its normal position,but will be insuificient to cause relay W to move the finger of itscontact 21 from the back point to the front point.

I will next assume that, with all parts of the apparatus again in thenormal condition, the operator attempts to reverse switch H but that themovement of switch H is obstructed in some manner, such, for example, asby a stone or a piece of coal, so that motor N draws an amount ofcurrent in excess of the normal operating current. Such current flowingin the reverse operating circuit previously traced for motor N willcause resistor 3| to be heated, thereby causing the resistance of unit3| to be increased, and hence still more of the excess current will flowthrough the winding of relay W until the current is of such a value asto cause relay W to open its contact 21 at the back point and to closethis contact at the front point.

With contact 2'! closed at the front point, current will flow throughholding winding 36 of relay W in the same direction as current flowsthrough pick-up winding 32 of relay W in the reverse operating circuitfor motor N, this stick circuit for relay W passing from terminal at,through contact 23 of relay m, contact 24 of relay m in its right-handposition, front point of contact 21 of relay W, winding 36 of relay W,contact 28 of relay m in its right-hand position, and contact 29 ofrelay m to terminal 0. The opening of contact 27 of relay W at its backpoint breaks the circuit previously traced for reverse switch relay 9,causing this relay to become deenergized. The holding circuit traced forrelay W through its winding 36 will remain closed until the operatoreither deenergizes relay m long enough to open its contacts 23 and 29,or energizes relay m by current of normal polarity.

I will now describe the operation of the form of apparatus shown in Fig.3. I will assume that the operator, desiring to reverse switch H moveslever Ic to its 1' position, causing relay m to be energized in thereverse direction and relay 9 to become energized.

With relay 9' energized, the reverse operating circuit for motormechanism N will be completed, passing from terminal a:, throughresistor 38 in multiple with the series path through resistor 31 andwinding 32 of relay W, front point of contact 34 of relay 9, armature 33of motor N, back point of contact 30 of relay 1, and field winding 35 ofmotor N to terminal 0. Under normal conditions of operation, the currentflowing in this circuit, although suflicient to cause switch H to beoperated to its reverse position, will be insufiicient to cause relay Wto open its contact Under normal operating conditions, the.

21 at the back its front point.

If, however, the movement of switch H should be obstructed, causingmotor N to draw an excessive amount of current, the larger part of suchcurrent, flowing through resistor 38, would cause this resistor tobecome heated. The resistance of unit 38 would, therefore, increase andcause a larger proportion of the current to flow through resistor 31 andwinding 32 until relay W would lift the finger of its contact 2'! fromthe back point to the front point; Such operation of contact 27 wouldcause relay g to become deenergized, thereby breaking the operatingcircuit for motor N which also constitutes a pick-up circuit for relayW. Itwill be noted that current in the stick circuit now completed forrelay W flows through the winding 36 of relay W in the same direction ascurrent in the operating circuit, just described for motor N, flowsthrough the winding 32 of relay W.

From the foregoing description and the accompanying drawing, it will beunderstood that with the arrangement of circuits shown for relay m, anovel method is provided for preventing storage of control for a railwaytrack switch. It will also be noted that I have provided a novel methodof overload protection for such a switch.

Although I have herein shown and described only three forms of railwayswitch controlling apparatus embodying my invention, it is understoodthat various changes and modifications may be made therein within thescope of the appended claims without departing from the spirit and scopeof my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway track switch, a polarized relay having aneutral armature and a polar armature, means manually controlled andalso controlled by said polar armature for energizing said relay foroperating said neutral armature, other means manually controlled andalso controlled by said neutral armature for energizing said relay foroperating said polar armature from each of its extreme positions to theother, locking means for at times rendering said other means ineffectiveto energize said relay, and switch operating means controlled by saidpolarized relay for moving said switch from each of its extremepositions to the other.

2. In combination, a railway track switch, a

point and close this contact at to the other.

3. In combination, a railway track switch, a manually controllableinstrument having 2, normal and a reverse position, a polarized relay, aneutral armature operated by said relay, a polar armature operated bysaid relay and having a normal and a reverse control position, meanscontrolled by said instrument and by said polar armature for energizingsaid relay for operating said neutral armature only when both saidinstrument and said polar armature are in their .75"

normal positions or when both are in their reverse positions, othermeans controlled by said neutral armature for energizing said relay foroperating said polar armature from each of its control positions to theother, locking means for at times rendering said other means ineffectiveto energize said relay, said switch operating means controlled by saidpolarized relay for moving said switch from each of its extremepositions to the other.

4. In combination, a railway track switch, a manually controllableswitch lever, a polarized switch control relay having neutral and polarcontacts and so constructed that the neutral contacts remain closed whenthe current supplied to the windings of said relay is reversed indirection, means controlled by normal and reverse polar contacts of saidpolarized switch control relay for operating said switch to normal andreverse positions respectively, and. normal and reverse control circuitsfor energizing said polarized relay controlled by normal and reversecontacts respectively of said switch lever and also controlled bytraflic conditions and including neutral contacts of said relay inmultiple with polar contacts of said relay for preventing controlstorage for said relay.

5. In combination, a railway track switch, a manually controllableswitch lever having a normal and a reverse position, normal and reversecontacts of said switch lever closed when said switch lever occupiessaid normal or said reverse position respectively,

a polarized switch control relay having neutral and polar contacts andso constructed that the neutral contacts remain closed when the currentsupplied to the windings of said relay is reversed in direction and thatwhen said relay is deenergized its polar contacts remain in the positionin which they were placed by the last previous energization of saidrelay, a locking relay, a normal control circuit for said polarizedrelay controlled by one of its own normal polar contacts and by a normalcontact of said lever, a reverse control circuit for said polarizedrelay controlled by one of its own reverse polar contacts and by areverse contact of said lever, a, second normal control circuit and asecond reverse controlcircuit for said polarized relay controlled by anormal, and a reverse contact respectively of said lever and eachcontrolled by a contact of said locking relay as well as by a neutralcontact of said polarized relay for preventing storage of control ofsaid polarized relay, andmeans controlled by normal and reverse polarcontacts of said polarized relay for operating said switch to normal andreverse positions respectively. V

6. In combination, a stretch of railway track, traffic governing meansfor controlling trafiic movements over said stretch, a polarized controlrelay having neutral and polar contacts and so constructed that itsneutral contacts remain closed when the current supplied to itswindings. is reversed in direction and that when said relay isdeenergized its polar contacts remain in the position in which they wereplaced by the last previous energization of its windings, a traiiicrelay controlled by trafiic conditions in said stretch, a normal controlcircuit for said polarized relay controlled by one of its own normalpolar contacts, a reverse control circuit for said polarized relaycontrolled by one of its own reverse polar contacts, a second normalcontrol circuit and a second reverse control circuit for said polarizedrelay each controlled by said traflie relay and by a neutral contact ofsaid polarized relay for preventing storage of control of said polarizedrelay, manually controlled means for supplying said normal and reversecontrol circuits with current of normal and reverse polarityrespectively, and means controlled by said polarized control relay forcontrolling said traflic governing means to permit a first or a secondtraflic movement over said stretch according as said polarized controlrelay is energized by current of normal or of reverse polarity.

'7. In combination, a stretch of railway track, traiiic governing meansfor controlling traffic movements over said stretch, a polarized controlrelay having neutral and polar contacts and so constructed that itsneutral contacts remain closed when the current supplied to its windingsis quickly, reversed in direction but will open if its windings remaindeenergized longer than a brief period of time and its polar contactswill remain in the position in which they were placed by the lastprevious energization of its windings, an auxiliary control contact,means for at times closing and for at other times opening said auxiliarycontrol contact, a normal control circuit for said polarized relaycontrolled by one of its own normal polar contacts, a reverse controlcircuit for said polarized relay controlled by one of its own reversepolar contacts, a second normal control circuit and a second reversecontrol circuit for said polarized relay each controlled by saidauxiliary control contact and by a neutral contact of said polarizedrelay for preventing storage of control of said polarized relay,manually controlled means for supplying said normal and reverse controlcircuits with current of normal and reverse polarity respectively, andmeans controlled by said polarized control relay for controlling saidtrafiic governing means to permit a first or a, second trafiic movementover said stretch according as said polarized control relay is energizedby current of normal or of reverse polarity.

8. In combination, a railway track switch, a polarized relay, manuallycontrollable means for energizing said relay by current of normal or ofreverse polarity, an overload relay having a pickup winding responsiveonly to current of greater magnitude than the normal operating currentfor said switch and also having a holding winding, a normal and areverse switch relay, a normal switch contact operated by said switchand closed at all times except when said switch occupies its reverseposition, a reverse switch contact operated by said switch and closed atall times except when said switch occupies its normal position, acontrol circuit for said normal switch relay controlled by said reverseswitch contact and by a normal polar contact of said polarized relay aswell as by a back contact of said overload relay and including anasymmetric unit to prevent the flow of current in the reverse directionin a given part of said circuit, a control circuit for said re-' verseswitch relay including a portion of the control circuit for said normalswitch relay and controlled by said normal switch contact and also by areverse polar contact of said polarized relay as well as by a backcontact of said overload relay and including an asymmetric unit in agiven part of the circuit to prevent the flow of current in the normaldirection, a normal and a reverse operating circuit for said switchcontrolled by said normal and reverse switch relays winding ofsaidoverload relay, and a stick circuit for said overload relay, controlledby said polarized relay and including the holding winding and a frontcontact of said overload relay.

9. In combination, a railway track switch, an overload relay having acontrol winding, a normal and a reverse switch relay, manuallycontrollable means controlled in part by a back contact of said overloadrelay for selectively energizing said normal and reverse switch relays,a source of current, a resistor having a positive temperaturecoefficient of resistance and having one of its ends connected to saidsource of current as well as having its other end connected to one endof said control winding and to a front contact of said normal switchrelay, a second resistor having a positive temperature coefficient ofresistance and having one of its ends connected to said source ofcurrent as well as having its other end connected to the other end of,said control winding and to a front contact of said reverse switchrelay, a normal operating circuit'ior said switch including said sourceof current and said resistors and control winding and also said frontcontact of the normal switch relay and then; passing through theoperating mechanisms for said switch and afterwards through a backcontact of said reverse switch :relay whereby said switch is operated toits normal position and said overload relay is energized sufiiciently tooperate its contacts if and only if said switch mechanism draws anexcessive amount of current, a reverse operating circuit for said switchincluding said source of current and said resistors and control windingand also said front contact of the reverse switch relay and then passingthrough the operating mechanism for said switch and afterwards through aback contact of said normal switch relay whereby said switch is operatedtoits reverse position and said overload relay is energized sufficientlyto operate its contacts if and only if said switch mechanism draws anexcessive amount of current, and a manually controlled stick circuit forsaid overload relay including a front contact of said overload relay.

10. In combination, a railway track switch, an overload relay having acontrol winding, a normal and a reverse switch relay, manuallycontrollable means controlled in part by a back contact of said overloadrelay for selectively energizing said normal and reverse switch relays,a

first and a second resistor each having a positive temperaturecoefficient of resistance, a normal operating circuit including saidfirst resistor in multiple with a series path through said secondresistor and the control winding of said overload .relay and controlledby a front contact of said normal switch relay whereby said switch isoperated to its normal position if a normal amount of current flows insaid normal operating circuit and contacts of said overload relay areoperated if and only if a greater amount of current flows,

.a reverse operating circuit including said second resistor in multiplewith a series path through said first resistor and the control windingof said overload relay and controlled by a front contact of said reverseswitch relay whereby said switch is operated to its reverse position ifa normal amount of current flows in said reverse operating circuit andcontacts of said overload relay are :operated if and only if a greateramount of cur- .rent flows,,and a manually controlled stick circuit forsaid overload relay.

7 11. In combination; a railway track switch, a manually controllablepole-changer comprising a normal and a reverse contact, an overloadrelay having a pick-up winding and also having a holding winding, anormal and a reverse control circuit for said switch controlled by saidnormal and reverse contacts, respectively and each including a backcontact of said overload relayya normal and a reverse operating circuitfor said switch controlled by said normal and reverse control circuitsrespectively and each including the pick-up winding of said overloadrelay whereby the contacts of said overload relay will be operated ifthe switch should stall and therefore draw an excessive amount ofelectric current, a normal stick circuit for said overload relaycontrolled by the normal contact of said polechanger and including theholding winding as well as a front contact of said overload relay, and areverse stick circuit for said overload relay controlled by the reversecontact of said polechanger and including the same holding winding aswell as a front contact of said overload relay.

12; In combination, a motor, a manually controllable normal contact, amanually controllable reverse contact, an overload relay having a pickupwinding and a holding winding, a normal and a reverse control circuitfor said motor controlled by said normal and reverse contactsrespectively and each including a back contact of said overload relay, anormal and a reverse operating circuit for said motor controlled by saidnormal and reverse control circuits respectively and each including thepick-up winding of said overload relay whereby the contacts of saidoverload relay will be operated if the motor is energized by current ofgreater magnitude than its normal operwinding of said overload relaywhereby said overi load relay is at times operated to open saidoperating circuits if said motor is energized by current of greatermagnitude than its normal operating current, and manually controllablenormal and reverse stick circuits including in common the holdingwinding of said overload relay for retaining said operating circuitsopen.

14. In combination, a railway track switch, a manually controllablepole-changer comprising a normal and a reverse contact, an overloadrelay having a pick-up winding and also having a holding winding, anormal and a reverse control circuit for said switch controlled by saidnormal and reverse contacts respectively and each including a backcontact of said overload relay, a

normal and a reverse operating circuit for said switch controlled bysaid normal and reverse control circuits respectively and each includingthe pick-up winding of said overload relay whereby the contacts of saidoverload relay will be operated if the switch should stall and thereforedraw an excessive amount of electric current, a stick circuit for saidoverload relay controlled by said pole-changer and including the holdingwinding as well as a front contact of said overload relay, and a trafficcontrolled contact for at times opening said stick circuit.

15. In combination, a railway track switch, a polarized control relay,manually controllable means for energizing said relay by current ofnormal or of reverse polarity, means controlled by traffic conditionsfor deenergizing said relay when said traffic conditions becomeunsuitable for said switch to be operated and for preventing subsequentenergization of said relay until said trafiic conditions again becomesuitable for said switch to be operated, a normal indication relay, acircuit controlled by a; normal polar contact of said control relay andby said switch in the normal position for energizing said normalindication. relay, a reverse indication relay, a circuit controlled by areverse polar contact of said control relay and by said switch in thereverse position for energizing said reverse indication relay. and meanscontrolled by a back contact of said normal indication relay and by aback contact oi said reverse indication relay as well as by normal andreverse polar contacts of said control relay for operating said switchto its normal and reverse positions.

16. In combination, a railway track switch, a polarized relay having aneutral armature and a polar armature arranged so that the polarity ofcurrent energizing said relay can be reversed without releasing theneutral armature, means manually controlled and also cont-rolled by saidpolar armature for energizing said relay for oper, ating said neutralarmature, other means manually controlled and also controlled by saidneutral armature for energizing said relay for moving said polararmature from each of its extreme positions to the other, and switchoperating means controlled by said polarized relay for moving saidswitch from each of its extreme positions to the other.

17. In combination, railway trafiic controlling apparatus, a polarizedrelay having a neutral armature and a polar armature arranged so thatthe polarity of current energizing said relay can be reversed withoutreleasing the neutral armature, manually controllable means forenergizing said relay to operate said neutral armature, means controlledin part by said neutral armature for energizing said relay to operatesaid polar armature, and means controlled by said polarized relay forselectively operating said trafiic controlling apparatus in a. first ora second given manner.

18. In combination, railway trafilc controlling apparatus, a polarizedrelay having a neutral armature and a polar armature, manuallycontrollable means for energizing said relay to operate said polararmature, means controlled in part by said polar armature for at timesenergizing said relay to operate said neutral armature, and meanscontrolled by said polarized relay for selectively operating saidtrafiic controlling apparatus in a first or a second given manner.

19. In combination, railway traffic controlling apparatus, a polarizedrelay having a neutral armature and a polar armature, means controlledin part by said neutral armature for at times en.- ergizing said relayto operate said polar armature from one of its extreme positions to theother, means controlled in part by said polar armature for at timesenergizing said relay to lift said neutral armature, and meanscontrolled by said polarized relay for selectively controlling saidrailway trafiic controlling apparatus in a first or a second givenmanner.

20. In combination, a polarized relay, means for energizing said relayin the normal or the reverse direction, a motor controlled by said relayand energized in the normal or reverse direction according as the relayis energized in the normal or reverse direction, a device for renderingsaid motor inoperative upon excessive current flow therein, a singleoverload winding of said device connected in series with said motor, anda single holding winding of said device energized in the normal orreverse direction when said device is operated according as said relayis energized in the normal or reverse direction.

21. In combination, a polarized relay, means for selectively energizingsaid polarized relay in the normal and reverse directions, a motor,means for reversibly supplying energy to said motor in accordance withthe direction of energization of said polarized relay, a normallyreleased overload relay efiective when picked up to prevent the supplyof energy to said motor, a winding of said overload relay connectedinseries with said motor to pick up the overload relay upon excessivecurrent flow in the motor, an auxiliary winding of said overload relay,a circuit for said auxiliary winding including a front contact of saidoverload relay and a normal polar contact of said polarized relay,another circuit for said auxiliary winding including said front contactand a reverse polar contact of said polarized relay.

HENRY S. YQUNG.

CERTIFICATE or CORRECTION; Patent No. 2,09T,826. November 2, 1957.

HENRY s. YOUNG It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows: Page 5, first column, line '7, claim 5, for the word "said"second occurrence, read and; and that the said Letters Patent should beread with this correction there in-that the same may conform to therecord of the case in the Patent Office.

Signed and sealed this 25th day of January,, A Da 1938,

v Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

